Getter and support



1958 w. E. BUESCHER ETAL 2,322,080

GETTER AND SUPPORT Filed June 27, 1956 INVENTORS WILLIAM E. BUESCHER DONALD R. KERSTETTER WAYNE H. KINGSLEY ATTORNEY GETTER AND SUPPORT Application June 27, 19st, SerialNo. 594,129

' 7 Claims '1'. 200 .4)

The inventionrelates togetters within tin/evacuated tube and more particularly to the assembly of getter ma terial and its support.

In one of the final processes in the manufacture of an evacuated electron tube it has been customary to flash vaporize therein a material, termed a getter, to remove the last traces of gases which may exist within the tube.

With the types of getter supports heretofore evolved there has been insufficient control of the flash resulting in loose particles being hurled out of the support and depositing on undesired portions of the electrode mount, resulting in the creation of interelectrode leakage paths and other undesirable characteristics.

it is an object of the invention to provide a getter with a support shield of such character as to provide for a directed flash and without possibility of loose particles of the getter material being exploded out of the support shield.

it is a further object to provide such a result regardless of whether the getter material itself be in powdered, paste or solid bar form.

These and other objects will become apparent upon consideration of the following specification when taken in conjunction with the accompanying drawing in which Fig. l is a perspective view of an evacuated electron tube prior to flashing of the getter material.

Fig. 2 is an elevational view of a portion of the same tube after flashing.

Fig. 3 is a plan view of a stamping utilized to form a support ring or shield for the getter material.

Fig. 4 is a section on the line 4--4 of Fig. 3.

Fig. 5 is a perspective view of a solid form of getter material which may be associated with the ring shield.

Fig. 6 is a plan view of the finally formed ring shield with getter material therein, and

Fig. 7 is a section through the structure of Fig. 6 on the line 7-7.

Referring to the drawings in greater detail at 10 there is indicated an electron tube with conventional electrode elements 12 therein and a top insulator 14 properly spacing the electrode elements apart. In the type of tube here illustrated there is provided a metal element 16 from which there is struck out a prop 18 for attachment to the getter shield. Insofar as the invention is concerned the particular form of support for the getter shield is immaterial so long as it lies in the region of the dome of the bulb. Attached to this support is a getter ring shield 20, the shield being preferably welded to the support by means of a strap tab 22 to be presently described in greater detail. In Fig. l, for the sake of showing the relationship and form of parts, the getter assembly is illustrated as in unflashed condition. In Fig. 2, the appearance of the top of the tube is shown, after getter flashing.

The getter shield is made out of metal strap material stamped as shown in plan in Fig. 3 and in section in Fig. 4. The strap comprises a bottom ring 24, a top United States Patent 73cc 2,822,080 Patented Feb. 4, 1958 to' be bent 'slightly as the washer is forced down-into the channel causing theedges of the tabs-to bite into the metal of the vertical walls of the channel and "thus lock the washer to the channel, as shown in Fig. 7. The

doubled overstrapitself'is again bent, as necessary, in

order that the tab can be welded to the prop 18 or other support within the tube with the shield structure parallel to the insulating spacer 14. The recesses 34 in the washer permit the flashed getter material to sweep in an upward and radial direction with respect to the shield so that a large volume of the tube above the electrodes is swept by the gas and there is formed on the interior wall of the envelope, at the domed portion, a condensation of the vaporized material, which in the practice of the invention extends to, but not below the level of the shield and is sharply cut off at that level, well above the level of the electrodes. The washer while forced into the channel still leaves enough space for the flashed vaporized getter material to flow between the washer and channel and to stream out of the recesses 34. However, loose particles of the getter, no matter what its physical form may be, are prevented from reaching the recesses and being expelled from the shield by reason of the retention of the solid material in the ring channel and the covering washer 26.

The getter material within the channel 32 may be in any of the known forms, powder, paste or solid bar. It is preferred that the same shall be in the form of a solid ring shaped bar such as shown at 40 in Figs. 5 and 7 since such a form leads to ease in handling and in assembling with the shield of the invention.

Having thus described the invention what is claimed as new is:

l. A getter and shield assembly comprising a ring channeled in cross section, with a deeper ring shaped central channel in the web of the ring, getter material in the central channel and a washer in the first channel extending from wall to wall of the channel and overlying the central channel and getter material, said washer having marginal recesses therearound.

2. A getter and shield assembly comprising a ring channeled in cross section, with a deeper ring shaped central channel in the web of the ring, getter material in the central channel and a washer in the first channel extending from wall to wall of the channel and overlying the central channel and getter material, said washer having marginal recesses therearound on its inner and outer margins.

3. A getter and shield assembly comprising a ring channeled in cross section, with a deeper ring shaped central channel in the web of the ring, getter material in the central channel and a washer in the first channel extending from wall to wall of the channel and overlying the central channel and getter material, said washer having marginal recesses therearound and tabs on the outer margin of the washer fitting snugly against the walls of the ring.

4. A getter and shield assembly comprising a ring channeled in cross section, with a deeper ring shaped central channel in the web of the ring, getter material in the central channel and a washer in the first channel e tending from wall ,to wall of the channel and overlying the central channel and getter material, said washer having marginal recesses therearound, tabs on the outer margin of the washer fitting snugly against the walls of the ring, and a tab integral with the ring and washer for securing the assembly to a support.

5. A getter and shield assembly comprising a ring channel provided with a second channel recessed in the web of the channel, getter material in said second channel, a washer overlying the second channel in close relationship to, the web of the first channel, and a margin of said washer being provided with alternating tabs and recesses with the tabs tightly engaging a wall of the first channel.

6. A getter and shield assembly comprising a ring channel provided with a second channel recessed in the web of the channel, getter material in said second channel, a washer overlying the second channel in close relationship to the web of the first channel, both inner and outer concentric margins of said washer being provided with. alternating recesses and tabs, with the tabs tightly engaging the walls of the first channel.

7, A getter and shield assembly comprising a ring channel provided with a second channel recessed in the web of the channel, getter material in said second channel, a washer overlying the second channel in close relationship to the web of the first channel, both inner and outer concentric margins of said Washer being provided with alternating recesses and tabs, with the tabs tightly engaging the walls of the first channel, and a tab integral with said washer and ring channel for securing the assembly to a support.

References Cited in the file of this patent UNITED STATES PATENTS 

